Battle of the Nile (47 BC)

The Battle of the Nile (February, 47 BC) was the decisive battle of the Alexandrine Civil War. Julius Caesar's 20,000-strong Roman-Egyptian-Pontic army and fleet defeated Ptolemy XIII's equally-large army and fleet on the banks of the Nile River in two linked engagements, and Ptolemy XIII drowned in the Nile while attempting to retreat. The battle left Caesar's lover Cleopatra as the sole ruler of Egypt.

History
In 48 BC, Julius Caesar arrived in Egypt with an army to hunt down his rival Pompey the Great and to mediate a dispute between co-rulers Ptolemy XIII and Cleopatra, who were fighting over the throne. Ptolemy's regent Pothinus presented Caesar with the severed head of Pompey, disgusting and angering him. Caesar later met Cleopatra, who was delivered to the royal palace wrapped in a rug, and she successfully courted his assistance in claiming the throne for her; the two also became lovers. Caesar defended Alexandria from a siege by Ptolemy's army, led by Achillas, and Caesar decided to have Pothinus executed for attempting to kill Cleopatra, while he sent Ptolemy and Theodotus of Chios to join their army near Alexandria, which was about to be attacked from two sides by both the Romans and the army of Mithridates I of the Bosporus. Caesar would take command of the Roman army and a fleet on the Nile as he prepared for the final battle with Ptolemy's army and fleet on the Nile Delta.

The Roman fleet and Egyptian fleet engaged in battle on the Nile River as the Roman legions set out to destroy Ptolemy's army, which used the natural defenses of a steep hilltop to protect themselves. The Egyptian fleet was destroyed, but all but one of the Roman troop transport ships were sunk, and the only surviving one retreated; the only Roman ship still alive was one meant for ranged combat, not one carrying any soldiers. Caesar decided to break the deadlock by having his army split in two, attacking the hill from the flanks. Caesar's mere presence inspired his men, and the Egyptian infantry struggled as they were outflanked, showered with arrows and javelins, and assaulted by war elephants. The Romans managed to destroy the Egyptian army, slaughtering its soldiers and sending out cavalry to pursue the fleeing remnants. Ptolemy drowned when his ship capsized during the retreat, allowing for Caesar to install Cleopatra on the throne of Egypt, with Ptolemy XIV as her nominal co-ruler. Caesar lingered in Egypt until April, enjoying a liaison with his mistress Cleopatra, before marching back towards Rome through Asia and fighting against new enemies such as Pontus.